Auger boring machine with two-stage guidance control system

ABSTRACT

An auger boring machine includes a two-stage guidance control system for controlling a pilot tube during formation of an underground pilot hole which is subsequently followed by an auger to form a larger hole for installation of underground pipe. The system includes a first stage guidance control mechanism for guiding the pilot tube during a first stage of driving the pilot tube and a second stage guidance control mechanism for guiding the pilot tube during a second subsequent stage of driving the pilot tube. The first stage mechanism typically includes a theodolite which allows for pilot tube control during the first several hundred feet of pilot hole formation. The second stage mechanism typically includes a sonar sensor such as a radio frequency receiver for sensing signals transmitted from within the pilot tube and allows for pilot tube control when the first stage mechanism is no longer functional.

BACKGROUND OF THE INVENTION

1. Technical Field

The invention relates generally to an auger boring machine and a methodof use in the trenchless installation of underground pipe. Moreparticularly, the invention relates to such a machine which utilizes apilot tube for forming a pilot hole for guiding the auger of themachine. Specifically, the invention relates to a two-stage guidancecontrol system for guiding the pilot tube through the earth to form apilot hole which is several hundred feet long.

2. Background Information

The use of an auger boring machine for installing underground pipebetween two locations without digging a trench there between is broadlyknown. In addition, it is known to use a pilot tube formed of aplurality of pilot tube segments to create a pilot hole for guiding anauger which bores a larger hole so that the auger remains within areasonably precise line and grade. For example, see U.S. Pat. No.6,206,109 granted to Monier et al. Commonly, a theodolite is used tocontrol the line and grade of the pilot tube in forming the pilot hole.However, the theodolite system has limitations in that when the pilothole extends past a certain distance, usually in the range of about 400feet, the illuminated target adjacent the pilot tube is too far away tobe properly sensed from the area of the pilot drive assembly. Thus, informing pilot holes which are extremely long, there is a need for aguidance control system to ensure that the remaining portion of thepilot hole remains on line and grade. The present invention solves thisand other problems in the art.

BRIEF SUMMARY OF THE INVENTION

The present invention provides an apparatus comprising: an auger boringmachine pilot tube; a first stage guidance control mechanism for guidingthe pilot tube during a first stage of driving the pilot tube; and asecond stage guidance control mechanism for guiding the pilot tubeduring a second subsequent stage of driving the pilot tube.

The present invention further provides a method comprising the steps of:(a) sensing a position of an auger boring machine pilot tube with afirst sensing device during a first stage of driving the pilot tube toform a pilot hole in the ground; (b) guiding the pilot tube during thefirst stage of driving the pilot tube in response to step (a); (c)sensing a position of the pilot tube with a second sensing device duringa second subsequent stage of driving the pilot tube; and (d) guiding thepilot tube during the second stage of driving the pilot tube in responseto step (c).

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a side elevational view of the auger boring machine of thepresent invention shown in a pit formed in the earth.

FIG. 2 is a top plan view of the auger boring machine.

FIG. 3 is a perspective view of the drive and control assembly.

FIG. 4 is a fragmentary sectional view showing a pilot tube segment withthe LED target disposed therein and connected to the sonde segment and atrailing pilot tube segment. FIG. 4 also illustrates the flow oflubricant through these segments of the pilot tube.

FIG. 5 is a sectional view taken on line 5-5 of FIG. 4 showing the LEDtarget within the pilot tube.

FIG. 6 is a side elevational view of the sonde segment of the pilottube.

FIG. 7 is a sectional view taken on line 7-7 of FIG. 6 and also includesthe connection of the sonde segment to the steering head and the pilottube segment which houses the LED target.

FIG. 8 is a sectional view taken on line 8-8 of FIG. 7.

FIG. 9 is a sectional view taken on line 9-9 of FIG. 8.

FIG. 10 is a top plan view of the pilot tube drive assembly prior toformation of the pilot hole.

FIG. 11 is a top plan view of the drive assembly showing an extension ofthe hydraulic actuators to provide an initial stage of pilot holeformation and also showing the steering capability of the pilot tube.

FIG. 12 is similar to FIG. 11 and shows the subsequent pilot tubesegment connected to the previously driven pilot tube segment and thedrive mechanism.

FIG. 13 is similar to FIG. 12 and shows the extension of the hydraulicactuators of the drive mechanism to drive the pilot tube with the newlyinstalled pilot tube segment thereof to lengthen the pilot hole.

FIG. 14 is a diagrammatic view showing the second stage of the guidancecontrol system in which the sonde transmits a signal to a receiver aboveground.

Similar numbers refer to similar parts throughout the drawings.

DETAILED DESCRIPTION OF THE INVENTION

The auger boring machine of the present invention is indicated generallyat 10 in FIGS. 1 and 2. Referring to FIG. 1, machine 10 is typicallydisposed in a pit 6 formed in the earth's soil or ground 8 andconfigured to bore a hole through ground 8 for the purpose of layingunderground pipe in the bored hole. Machine 10 typically bores a holefrom within a pit such as pit 6 to another pit which is spaced severalhundred feet away. Machine 10 includes a frame 12 which extends from afront end 14 to a rear end 16 of machine 10. Front and rear end 14 and16 define there between an axial direction of machine 10. Machine 10further has first and second opposed sides 18 and 20 (FIG. 2) definingthere between a lateral direction of machine 10.

An engine compartment 22 is mounted on frame 12 and houses therein afuel powered engine 24, an electric generator 26 powered by engine 24and a hydraulic pump 28 also powered by engine 24. An auger drivecompartment 30 is disposed in front of compartment 22 and houses thereinan auger drive having a rotational output shaft 32 for rotationallydriving an auger 34 (FIG. 25). Frame 12 further includes a pair ofspaced axially extending rails 36 secured to a plurality of cross bars38 which are mounted on ground 8 in the bottom of pit 6. A pair ofadjustable stabilizing poles 40 are telescopically received in andadjustably mounted respectively on rails 36 and configured to pressagainst the wall of ground 8 which bounds pit 6.

In accordance with a feature of the invention, a two-stage pilot tubeguidance control and drive assembly 42 is mounted on frame 12, and moreparticularly is removably mounted on rails 36 via mounting legs 44 (FIG.3) which are removably insertable into openings 46 formed in each ofrails 36. Mounting legs 44 and the mounting mechanism of which they area part are described in further detail in the copending applicationentitled Pilot Tube System And Attachment Mechanism for Auger BoringMachine which is incorporated herein by reference and filed concurrentlyherewith. Assembly 42 when mounted on frame 12 is positioned so that acentral axially extending axis X of a pilot tube 48 is coaxial with anaxially extending axis Y which passes centrally through output shaft 32and about which shaft 32 is rotated when driving an auger and cuttinghead (not shown). Assembly 42 includes a generally circular rear plate50 which abuts compartment 30 when assembly 42 is mounted on frame 12.

Assembly 42 includes front and rear mounting assemblies 52 and 54 whichare seated on rails 36 of frame 12 when assembly 42 is mounted on frame12. A pair of axially extending parallel spaced rails 56 and 58 arerigidly mounted on assemblies 52 and 54. Adjustable stabilizing poles 60are telescopically mounted respectively within first and second rails 56and 58 and are adjustable to provide force against ground 8 in the samemanner as poles 40.

A rigid front cross member 62 extends between and is connected to eachof rails 56 and 58 adjacent the front thereof with a front pilot tubesupport 64 mounted thereon centrally between rails 56 and 58. Support 64includes a plurality of bearings which engage the pilot tube 48 to allowaxial movement of tube 48 as well as rotational movement of tube 48about axis X to allow for the steering thereof. Rear plate 50 andassociated structure attached thereto serve as a rear cross member forrigidly connecting rails 56 and 58 to one another at the rear ofassembly 42. An intermediate cross member 66 extends laterally betweenrails 56 and 58 and is supported respectively on rails 56 and 58 byfirst and second roller assemblies 68 and 70. Each roller assemblyincludes a pair of upper rollers 72 and lower rollers 74 whichrespectively rollingly engage upper and lower surfaces 76 and 78 ofrespective rails 56 and 58.

An electric guidance control motor 80 having a rotational drive ismounted on cross member 66 for selectively rotating pilot tube 48 ineither direction about axis X. A lubricant feed swivel 82 having alubricant inlet 84 is mounted on motor 80 by a pair of spaced mountingrods 86 extending forward from motor 80. Swivel 82 is connected to pilottube 48 and thus serves as an engaging member for drivingly engagingtube 48 during operation of assembly 42. Inlet 84 of swivel 82 is influid communication with a lubricant feedline which is in fluidcommunication with a source of lubricant, which is typically water.Swivel 82 receives water through inlet 84 to pump the water throughpilot tube 48 and through a steering head 88 connected to the front ofpilot tube 48, the water flowing out a forward exit opening 90 and aplurality of lateral exit openings 92. A crane stand 94 is mounted onthe frame of assembly 42 for supporting a crane (not shown) used forlifting pilot tube segments into position for connecting the varioussegments to form pilot tube 48 during the process of driving tube 48 toform the pilot hole. A cord carrier 96 is mounted atop rail 56 andincludes a plurality of links 98 which are pivotally connected to oneanother so that electrical cords for powering motor 80 and otherelectrical components will not become tangled during the longitudinaldriving of pilot tube 48.

In accordance with the invention, during the first stage of drivingpilot tube 48, a steering mechanism keeps tube 48 on line and gradeusing a theodolite which utilizes a camera 100 in electricalcommunication with a display monitor 102 which displays the view of thecamera through pilot tube 48 of an illuminated LED target 104 (FIGS.4-5) disposed within pilot tube 48 adjacent steering head 88. In orderfor camera 100 to view light rays transmitted from LED target 104, pilottube 48 is hollow, as are the other structures intermediate camera 100and target 104, such as motor 80 and swivel 82, in order to provide aline of sight Z (FIGS. 4, 11, 13) between camera 100 and target 104. Aguidance control unit 106 is mounted on rail 58 and includes manuallyoperable controls 108 typically in the form of joysticks in electricalcommunication with motor 80 in order to send a signal to motor 80 tocontrol rotation of pilot tube 48.

Assembly 42 includes a continuous stroke drive mechanism 110 comprisinga pair of hydraulic actuators in the form of piston-cylindercombinations 112 powered by pump 28. Combinations 112 must provide asubstantial amount of forward and reverse thrust. For example, theforward thrust produced by combinations 112 on one preferred embodimenthas a maximum thrust of 280,000 pounds while the reverse thrust has amaximum thrust of 140,000 pounds. Combinations 112 are capable of acontinuous stroke throughout the extension thereof and likewise duringthe retraction thereof. The continuous stroke drive mechanism of thepresent invention is described in further detail in the copendingapplication entitled Method And Apparatus For Providing A ContinuousStroke Auger Boring Machine which is incorporated herein by referenceand filed concurrently herewith.

In accordance with the invention, pilot tube 48 includes atarget-containing pilot tube segment 122 and a sonde segment 125removably connected to the leading end of segment 122 and the trailingend of steering head 88. The various pilot tube segments of pilot tube48 are connected end to end to sequentially increase the length of pilottube 48 during the driving process. Typically, all or nearly all of thepilot tube segments are of the same length and are interchangeable withone another. However, some of the pilot tube segments may be of adifferent length. Segments 122 and 125 are shorter than the standardpilot tube segments 124 connected sequentially behind segment 122. Pilottube segment 122 has a length of roughly two feet while segment 125 isroughly three feet long and pilot tube segments 124 typically come inlengths of five feet although this may vary.

As noted previously, pilot tube 48 is configured with lubricant throughpassages to allow a lubricant such as water to flow therethrough tosteering head 88. The lubrication system of assembly 42 is described infurther detail in the copending application entitled Lubricated PilotTubes For Use With Auger Boring Machine Pilot Steering System which isincorporated herein by reference and filed concurrently herewith.However, some of the lubricant passages of pilot tube 48 are discussedherein. More particularly, FIG. 5 shows a sectional view of a trailingportion of sonde segment 125, segment 122 and a leading portion of apilot tube segment 124, which in part shows the lubricant passagestherethrough. Segment 122 has a first trailing coupling member 130 whichthreadably engages a second leading coupling member 132 of the leadingsegment 124 to connect segments 122 and 124 together. Six lubricantpassages 140 are formed in first coupling member 130 and arecircumferentially equally spaced from one another. A central throughpassage 162 is formed in pilot tube segment 124. Six lubricant passages164 are also formed in segment 124 radially outwardly of passage 162 andare circumferentially evenly spaced from one another in order to alignwith passages 140 when first and second coupling members 130 and 132 arejoined to one another.

FIG. 5 shows additional passages in pilot tube 48 allowing for a flow oflubricant therethrough to steering head 88. More particularly, sixlubricant passages 172 are formed through segment 122 in a mannersimilar to passages 140 and passages 164 in order to allow communicationwith passages 140 of coupling member 130. Passages 172 are disposedradially outwardly of a central interior chamber 173 which is formed insegment 122 and which houses target 104. Passages 172 merge into acentral chamber 174 formed in the rear portion of sonde segment 125 viarespective passages 176 which extend radially outwardly from chamber174. FIG. 4 further shows that lead tube segment 122 defines a centralpassage providing for line of sight Z therethrough to provide a clearview of illuminations 180 (FIG. 5) of target 104.

Referring to FIGS. 6-9, sonde segment 125 and steering head 88 arefurther described. Segment 125 has a substantially solid cylindricalmain body 134 which makes up most of its length. Body 134 has a leadingend 136 and a trailing end 138 with a mounting neck 140 extendingrearwardly from trailing end 138. Neck 140 is stepped inwardly from body134 and is also substantially cylindrical. Neck 140 defines a pair ofaxially spaced annular grooves in which are disposed a respective pairof annular seals 142. Neck 140 further defines an annular groove 143between seals 142 in communication with each of passages 176. Aneck-receiving cavity 144 is formed in body 134 and extends rearwardlyfrom leading end 136 for receiving therein a neck 146 of steering head88 which is similar to neck 140 of segment 125. Body 134 defines acentral transmitter cavity 148 which is in communication with cavity 144and in which a radio frequency (RF) transmitter 150 is disposed. Sixaxially elongated transmission slots 152 are formed in body 134 andextend radially outwardly from cavity 148 to the outer surface of body134. Slots 152 are circumferentially equally spaced from one another.

Central chamber 174 converges into a central passage 154 which extendsfrom chamber 174 into the rear portion of body 134. Six radial passages156 (only four shown) communicate with and extend radially outwardlyfrom central passage 154 respectively to six axially extending passages158 which extend forward therefrom to adjacent leading end 136 of body134. Passages 158 are circumferentially evenly spaced from one anotherand each passage 158 is positioned centrally between an adjacent pair ofslots 152. Another set of six radial passages 160 are formed in thecylindrical wall which bounds cavity 144 and extend respectivelyradially inwardly from passages 158 to cavity 144. Similarly, a set ofsix radial passages 166 are formed in the cylindrical portion of pilottube segment 122 which defines a front portion of interior chamber 173and extend respectively radially inwardly from the leading ends ofpassages 172 to interior chamber 174. Passages 166 thus communicate withannular groove 143 of mounting neck 140. Pilot tube segments 122 and 125are connected, to one another by a plurality of bolts 168 extendingthrough holes formed in segment 122 and threadably engaging threadedholes 170 formed in neck 140.

Referring to FIGS. 7 and 9, steering head 88 is further described.Steering head 88 includes a head portion 188 from which neck 146 extendsrearwardly. Portion 180 includes a flat, oval-shaped forward facingsteering face 182 (FIG. 3) which angles from a tip 184 on one side ofportion 180 rearwardly across to the other side of portion 180. Likeneck 140 of segment 125, neck 146 defines a pair of axially spaceannular grooves in which a pair of annular seals 186 are respectivelydisposed. Another annular groove 188 is formed in the cylindrical outersurface of neck 146 between seals 186 and communicates with passages 160when steering head 88 is connected to segment 125. Six radial passages190 are formed in neck 146 and extend radially inwardly from groove 188and respectively adjacent passages 160 to a central interior chamber 192formed in neck 146 and a rear portion of head portion 180. A centralpassage 194 extends forward from chamber 192 and then branches into aplurality of exit passages 196 formed in head portion 180. One of exitpassages 196 extends forward to exit opening 90 (FIG. 3) and theremaining passages 196 extend to respective exit openings 192 on theouter surface of head portion 80. A plurality of bolts 198 extendthrough holes formed in the front portion of segment 125 and intorespective threaded holes in neck 146 of steering head 88 to connectsteering head 88 and segment 125 to one another.

Thus, segments 122 and 125 and steering head 88 are configured withvarious lubricant passages to allow the flow of lubricant particularlyin the form of water to flow from lubricant feed swivel 82 all the wayto the outer surface of steering head 88 while allowing target 104 andtransmitter 150 to be disposed within pilot tube 84 separate from theflow of the water. The arrows in FIGS. 5 and 7 indicate the flow oflubricant through the various passages from swivel 82 through pilot tube48 and steering head 88.

The operation of boring machine 10 is now described with reference toFIGS. 10-14. FIGS. 10-13 are shown without main frame 12 of machine 10for simplicity. FIG. 10 shows assembly 42 prior to the driving of pilottube 48 to form a pilot hole with an operator 204 preparing to beginoperation of assembly 42. The pistons of piston cylinder combinations112 are shown in a fully retracted position FIG. 10. Assembly 42 isoperated to actuate combinations 112 in order to extend pistons 116thereof to drive pilot tube 48 into ground 8 as indicated in arrow E inFIG. 11 to form the initial stages of a pilot hole 206. During theextension of pistons 116 and pilot tube 48, camera 100 senses orreceives input in the form of light rays from LED target 104 and relaysthe images of illuminations 180 on the monitor 102. Operator 204 viewsdisplay monitor 102 in order to determine the position or orientation ofpilot tube 48 and thus whether steering head 88 needs to be adjusted tomaintain the line and grade of pilot tube 48. Operator 204 uses controls108 in order to make any necessary adjustments, specifically rotatingpilot tube 48 as indicated in arrow F in FIG. 11 via motor 80.Simultaneously with driving and steering pilot tube 48, water may bepumped through the lubricant through passages in pilot tube 48 viaswivel 82 to steering head 88 and through the exit openings thereof inorder to facilitate the formation of pilot hole 206. At this early stageof pilot hole formation, only one of the standard size pilot tubes 124Ais being used, as shown in FIGS. 10 and 11.

Once the initial driving of tube 48 is performed, pistons 112 areretracted as shown in FIG. 12 at arrow G and a pilot tube segment 124Bis connected to tube segment 124A and a rotatable portion of swivel 82as indicated at arrow H in preparation for additional driving of tube48. Drive mechanism 110 is then operated to extend piston 116, rollerassemblies 68 and 70 and pilot tube 48 including segments 124A and B tolengthen pilot hole 206 as indicated at arrow J in FIG. 13 whileoperator 204 provides any rotational adjustment to steering head 88 asindicated at arrow K. The pattern of adding tube segments and continuingto drive pilot tube 48 goes on until the pilot hole is completed or moreparticularly so that the pilot tube 48 extends out of ground 8 so thatsections of pilot tube 48 may be removed as the auger boring operationis underway and thus moves pilot tube 48 gradually forward.

However, pilot tube 48 may only be controlled by the theodolite controlassembly to maintain a proper line and grade thereof for a certaindistance, which is typically about 400 feet from camera 100, asrepresented by D1 in FIG. 14 although camera 100 is not shown in FIG.14. When the distance is too far for camera 100 to sense theilluminations 180 (FIG. 5) of target 104, the second stage of guidancecontrol of pilot tube 48 comes into play. At this point, transmitter 150emits an RF signal as indicated at the dotted line in FIG. 14 which isreceived by an RF receiver 208 carried by a second operator 218 aboveground. Thus, as pilot tube 48 is driven forward as indicated at arrow Lin FIG. 14, second operator 210 walks along as indicated at arrow M withreceiver 208 in order to receive the transmitter signal and thusdetermine the position of pilot tube 48 at its leading end in order todetermine how it should be steered. Operator 210 then communicates thefindings to operator 204 by any suitable means of communication or aremote control may be used in order to control motor 80 in rotatingpilot tube 48 to keep pilot tube 48 on a proper line and grade duringthe remainder of driving the pilot tube to complete pilot hole 206.

Once pilot hole 206 is completed, assembly 42 is removed from frame 12of auger boring machine 10 and an auger is then connected to arotational output shaft powered by engine 24 along with the pipe orcasing in which the auger is disposed and cutting head connected to thefront of the auger. A swivel is also connected to the trailing end ofpilot tube 48 and the front of the cutting head to allow for therotation of the auger and cutting head independent of rotating pilottube 48. The swivel is described in greater detail in the copendingapplication Method of Installing Large Diameter Casing and Swivel ForUse Therewith which is incorporated herein by referenced and filedconcurrently herewith.

In the foregoing description, certain terms have been used for brevity,clearness, and understanding. No unnecessary limitations are to beimplied therefrom beyond the requirement of the prior art because suchterms are used for descriptive purposes and are intended to be broadlyconstrued.

Moreover, the description and illustration of the invention is anexample and the invention is not limited to the exact details shown ordescribed.

1. An apparatus comprising: an auger boring machine pilot tube; a firststage guidance control mechanism for guiding the pilot tube during afirst stage of driving the pilot tube; and a second stage guidancecontrol mechanism for guiding the pilot tube during a second subsequentstage of driving the pilot tube.
 2. The apparatus of claim 1 furthercomprising a radio frequency transmitterwithin the pilot tube; and anilluminated target within the pilot tube.
 3. The apparatus of claim 2further comprising a radio frequency receiver separate from the pilottube and operationally connected to the transmitter for receiving radiofrequency signals therefrom.
 4. The apparatus of claim 3 wherein thepilot tube has leading and trailing ends; and further comprising a lineof sight passage formed in the pilot tube from the target to thetrailing end; and a camera adjacent the trailing end of the pilot tubeand aligned for viewing the target through the line of sight passage. 5.The apparatus of claim 4 further comprising a motor having a rotationaldrive operatively connected to the pilot tube for rotating the pilottube.
 6. The apparatus of claim 2 wherein the pilot tube has an outersurface; and further comprising a plurality of transmission openingsformed in the pilot tube extending from the transmitter to the outersurface of the pilot tube.
 7. The apparatus of claim 2 furthercomprising at least one lubrication through passage formed in the pilottube extending alongside the transmitter and the target.
 8. Theapparatus of claim 2 wherein the pilot tube has leading and trailingends; and the transmitter is disposed between the leading end and thetarget.
 9. The apparatus of claim 8 further comprising a steering headon the leading end of the pilot tube; and wherein the transmitter isdisposed between the steering head and the target.
 10. The apparatus ofclaim 9 wherein the pilot tube comprises a first pilot tube segmentwhich carries the transmitter and is removably connected to the steeringhead; and a second pilot tube segment which carries the target and isremovably connected to the first pilot tube segment.
 11. The apparatusof claim 1 wherein the first stage mechanism comprises a theodolite; andthe second stage mechanism comprises a sonar sensor.
 12. A methodcomprising the steps of: (a) sensing a position of an auger boringmachine pilot tube with a first sensing device during a first stage ofdriving the pilot tube to form a pilot hole in the ground; (b) guidingthe pilot tube during the first stage of driving the pilot tube inresponse to step (a); (c) sensing a position of the pilot tube with asecond sensing device during a second subsequent stage of driving thepilot tube; and (d) guiding the pilot tube during the second stage ofdriving the pilot tube in response to step (c).
 13. The method of claim12 wherein step (a) comprises the step of sensing the position of thepilot tube with a theodolite.
 14. The method of claim 13 wherein step(c) comprises the step of sensing the position of the pilot tube with asonar sensor.
 15. The method of claim 13 wherein step (c) comprises thestep of sensing a radio frequency transmission from within the pilottube.
 16. The method of claim 15 wherein step (c) comprises the step ofsensing the radio frequency transmission with an above ground radiofrequency receiver.
 17. The method of claim 12 wherein step (a)comprises the steps of transmitting light rays through the pilot tubefrom adjacent a leading end thereof to adjacent a trailing end thereof;and calculating the position of the pilot tube based on the light rays.18. The method of claim 17 wherein step (c) comprises the step ofsensing a radio frequency signal transmitted from the pilot tubeadjacent its leading end.
 19. The method of claim 12 wherein step (c)comprises the step of sensing a radio frequency signal transmitted fromthe pilot tube adjacent its leading end.
 20. The method of claim 12wherein each of steps (b) and (d) comprises the step of rotating thepilot tube and a steering head mounted thereon.